BOARD_SIZE = 15
board = []


def initBoard():
    for i in range(BOARD_SIZE):
        row = ["╋"] * BOARD_SIZE
        board.append(row)


def printBoard():
    for i in range(BOARD_SIZE):
        for j in range(BOARD_SIZE):
            print(board[i][j], end='')
        print()


initBoard()
printBoard()
inputStr = input("请输入您下棋的坐标，应以x,y的格式：\n")
while inputStr is not None:
    try:
        x_str, y_str = inputStr.split(sep=',')
        if board[int(y_str) - 1][int(x_str) - 1] != '╋':
            inputStr = input("您输入的坐标点已有棋子了，请重新输入\n")
            continue
        board[int(y_str) - 1][int(x_str) - 1] = '●'
    except Exception:
        inputStr = input("您输入的坐标不合法，请重新输入，下棋坐标应以x,y的格式\n")
        continue
    printBoard()
    inputStr = input("请输入您下棋的坐标，应以x,y的格式：\n")